加入案例查询

Question

在我的查询中，我必须检查三个条件并加入，哪里是常见的..但是这个

中有一些错误

 select 
 count(case when interview_status = 1 then applicant_id else null end) as selected,
 count(case when interview_status = 2 then applicant_id else null end) as rejected,
 count(case when interview_status = 3 then applicant_id else null end) as not_attented,
 JOIN appointment ON appointment.applicant_id=student_application.applicant_id,
 WHERE filter_status=1 AND appointment_status !=0
 from student_application;

但是这显示了一些错误

Answer 1

1. 我看到了额外,的问题。

2. from子句应在where之前

   select 
   count(case when interview_status = 1 then applicant_id else null end) as selected,
   count(case when filter_status = 2 then applicant_id else null end) as rejected,
   COUNT(CASE WHEN FILTER_STATUS = 2 THEN APPLICANT_ID ELSE NULL END) AS NOT_ATTENTED
   from student_application
   JOIN appointment ON appointment.applicant_id=student_application.applicant_id
   WHERE FILTER_STATUS=1 AND APPOINTMENT_STATUS !=0;